#  Copyright 2012 Eric Lawrey, Australian Institute of Marine Science
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.

# Overwrite the contents of the initialTable with the contents of the 
# overwriteCsv file. Columns that are not common are retained and empty
# cells are filled with ""
overwriteDataFrameWithCsvFile <- function(initialTable, overwriteCsv) {
# Merge initial data frame with spreadsheet table
  if (!is.na(overwriteCsv)) {
    overWriteTable <- read.csv(overwriteCsv, stringsAsFactors=FALSE)
    templateTable <- overwriteDataframes(initialTable, overWriteTable)
  } else {
    templateTable <- initialTable
  }
  # Make any resulting NA correspond to empty strings so they will be
  # fill vertically correctly.
  templateTable[is.na(templateTable)] <- ""
  return(templateTable)
}

